Ok so today I got an email saying my flight time had moved up by 2.5 hours so I went to see if that was just for my departure day or also the next day. During the process I noticed the fare had dropped from $4585 down to $4125, I called Qatar to get the difference back but they said no.

So then I looked at my cancellation options and with a voucher I will get $5000 (ish) back.. so why wouldn't people just book a flight, cancel the ticket for a voucher and then rebook the same flight again with left over money on the voucher for a future booking?

Am I missing something?

Thank you!